Drill 9 · Reading & Writing · Hard Command of Evidence
SAT Reading & Writing: Hard Command of Evidence (Drill 9) is a Reading & Writing practice drill covering Hard Command of Evidence. It contains 5 original questions created by Brian Stewart, a Barron's test prep author with over 20 years of tutoring experience.
Five hard Command of Evidence questions covering new findings and two data displays. The tempting wrong answers stay on topic but answer a question the claim did not ask. For the graph and table items, find the comparison the argument actually rests on before choosing.
Nighttime temperatures in a city's dense center stay noticeably warmer than in the surrounding countryside. Meteorologists proposed that the city's pavement and buildings absorb heat during the day and release it slowly at night, keeping the center warm after dark. A colleague suggested the center might just sit in a naturally milder pocket of the region, warmer day and night alike.
Question 1. Which finding, if true, would most directly support the meteorologists' proposal?
Explanation: Choice C is the best answer because the proposal is that stored daytime heat released at night keeps the center warm, so the evidence must show the warmth is specific to night. The center and countryside reaching nearly the same daytime temperature and diverging only after sunset fits heat being absorbed by day and released at night, and rules out the center simply being a milder pocket warm around the clock. Choice A is wrong because parks and trees among the streets would tend to cool the center, if anything, and do not show stored heat warms it at night. Choice B is wrong because what the surrounding countryside is used for is background and does not tie the warm nights to the city's stored heat. Choice D is wrong because summer nights being warmer than winter nights reflects the seasons, not the day-to-night heat release the proposal names.
Agronomists tested whether planting a winter cover crop would raise the nitrogen available in the soil by spring, and whether the benefit depends on soil type. They measured spring nitrogen after a bare-fallow winter and after a cover-crop winter on three soil types. They concluded that the cover crop helps mainly on sandy soil, reasoning that a practice worth recommending for sandy ground should raise nitrogen far more there than on soils that already hold nitrogen well.
Question 2. Which choice best describes data from the graph that support the agronomists' conclusion?
Explanation: Choice D is the best answer because the conclusion is that the cover crop helps mainly on sandy soil, which is a difference across soil types in how much it raises nitrogen. The graph shows a large gain on sand, about 14 to 31, but only small gains on loam, about 22 to 27, and clay, about 25 to 28, exactly the soil-specific benefit claimed. Choice A is wrong because the cover-crop level on sand alone is a single bar and does not compare the gain there with the gains on other soils. Choice B is wrong because higher nitrogen under the cover crop on all three soils is true but does not show the benefit is concentrated on sand. Choice C is wrong because clay holding the most nitrogen under bare fallow describes one condition and does not compare the gains from the cover crop.
A team noticed that its athletes who perform a long pre-game stretching routine suffer fewer muscle injuries than those who skip it. The trainers concluded that the stretching routine prevents injuries, proposing that loosening the muscles beforehand protects them during play. They planned to make the routine mandatory for everyone.
Question 3. Which finding, if true, would most directly weaken the trainers' conclusion?
Explanation: Choice D is the best answer because the conclusion is that the routine prevents injuries, so a finding that the injury-prone athletes were the ones skipping it shows the gap may come from who chose to stretch rather than from the stretching, undercutting the cause. Choice A is wrong because where the athletes complete the routine is a background detail that says nothing about whether the stretching prevents injuries. Choice B is wrong because describing the routine's length and targets restates what it is without testing whether it prevents injuries. Choice C is wrong because how this sport's injury rate compares with other sports does not address whether the routine works here.
Average Reduction in Commute Time (min) by Corridor and Measure
| Corridor | Added bus route | Dedicated bus lane |
|---|---|---|
| North corridor | 4 | 13 |
| East corridor | 7 | 9 |
| South corridor | 8 | 6 |
A transit agency compared two measures by how many minutes each trimmed from the average commute in three corridors. The director wanted to know where a dedicated bus lane was clearly the better measure rather than simply adding another bus route. The data show that the dedicated lane outperformed the added route by the widest margin in ________
Question 4. Which choice most effectively uses data from the table to complete the statement?
Explanation: Choice B is the best answer because the statement asks where the dedicated lane beat the added route by the widest margin. The lane's advantage is 9 minutes in the North corridor, 13 against 4, but only 2 minutes in the East and negative in the South, so the North corridor is where the lane most clearly wins. Choice A is wrong because the South corridor's lane reduction of 6 is its smallest, but the question asks about the margin over the added route, not the raw reduction. Choice C is wrong because the East corridor shows the lane only slightly ahead, a narrow margin, not the widest. Choice D is wrong because the South corridor is the one place the added route beat the lane, the opposite of the widest lane margin.
A small town's population grew quickly over a decade. Demographers proposed that the growth came mainly from people moving in from elsewhere, drawn by new jobs at a nearby plant, rather than from families in town having more children. They wanted to confirm that newcomers, not a local baby boom, accounted for the rise.
Question 5. Which finding, if true, would most directly support the demographers' proposal?
Explanation: Choice B is the best answer because the proposal is that newcomers drove the growth rather than a local rise in births, so the evidence must tie the increase itself to in-migration. Most of the net population increase consisting of people who moved in from elsewhere directly establishes that migration, not a baby boom, accounts for the rise. Choice A is wrong because a record-high total population restates that the town grew without showing whether newcomers or births caused it. Choice C is wrong because the plant's large workforce is background that fits the migration story but does not by itself show the residents moved in. Choice D is wrong because new schools and clinics are a response to growth and do not reveal whether the growth came from migration or births.